Republican senators (from l.) Sen. John Thune of South Dakota, John Barrasso of Wyoming, John McCain of Arizona, and John Hoeven of North Dakota walk from the floor to a closed-door caucus after a compromise between the Democratic majority and the GOP minority on filibuster rules, at the Capitol on Tuesday, July 16, 2013. Senate Majority Leader Harry Reid credited Senator McCain with helping broker a breakthrough.

Washington — Senate leaders stepped back Tuesday from the brink of the "nuclear option" abyss, working out a deal that will allow Democrats to confirm a handful of controversial presidential appointees. It will also keep existing filibuster rules intact, ending majority leader Harry Reid's drive to make changes that critics said would wipe away any impetus for compromise in the Senate.

The deal, coming just hours before Senator Reid might have pulled the trigger on the so-called nuclear option, represents a victory for Democrats who have been seething about Senate foot-dragging in confirming President Obama's nominees.

The pact’s larger import, however, is limited. It does not, for example, prevent future challenges to executive-branch nominees from the GOP minority or change the Senate rules in any way.

Indeed, the most liberal senators, who see rules of the Senate as overly restrictive, no doubt would have preferred the nuclear option – which would allow a rule change by vote of 51 senators, a bare majority, rather than the usual 67.

"There is, I would say, no assurance that we won’t be in this place again but it is our hope that this will serve as a model," says Sen. Jeff Merkley (D) of Oregon, an avid supporter of reforming the Senate's rules who nonetheless endorsed the compromise on Tuesday. "The value of it is that both sides understand that if the process is abused, we will back to the same place again."

The deal allows most of Mr. Obama's pending executive-branch nominees to be confirmed, but it requires the White House to drop two nominees to the National Labor Relations Board (NLRB), whose recess appointments by the president were controversial, in favor of two new picks. Negotiations were led on the GOP side by Sen. John McCain of Arizona and on the Democratic side by Sen. Charles Schumer of New York and Reid.

Reid did not promise to eschew rule changes in the future, nor did Senate Republicans pledge to allow up-or-down votes on presidential nominees.

Reid had threatened to change the rules to confirm presidential appointees with a simple majority of senators, instead of the 60-vote supermajority now required when Republicans filibuster a nominee. But changing Senate rules with a simple majority marks a departure from Senate precedent that some Senate traditionalists worried would open the door to future Senate leaders also allowing judges or legislationto pass with only 51 votes.

The accord came after a rare, all-senators meeting Monday evening in the Old Senate Chamber that lasted nearly four hours. Some three dozen senators rose to speak behind the chamber's heavy doors, a rare level of direct and sustained debate for members of the "world’s greatest deliberative body."

Afterward, many senators from both parties credited the meeting, requested by Sens. Roger Wicker (R) of Mississippi and Bob Corker (R) of Tennessee, with showing the leadership of both parties that the rank-and-file heavily favored a compromise.

Richard Cordray was the first beneficiary of the deal. He was named director of the Consumer Financial Protection Bureau (CFPB) in a controversial (and possibly illegal) recess appointment in January 2012. His nomination advanced to a final Senate vote by a 71-to-29 margin on Tuesday morning.

Other nominees set to be approved include Gina McCarthy to head the Environmental Protection Agency (EPA), Tom Perez to lead the Department of Labor, Fred Hochberg to direct the Export-Import Bank, and Mark Pearce to join the National Labor Relations Board (NLRB).

Two other nominees to the NLRB previously appointed under the same circumstances as Mr. Cordray – Richard Griffin and Sharon Block – would see their nominations withdrawn in exchange for Republicans promising votes on two new NLRB nominees before the Senate adjourns for the August recess. Politico is reporting that Obama will nominate Nancy Schiffer and Kent Hirozawa. Ms. Schiffer is the associate general counsel at the AFL-CIO, and Mr. Hirozawa is the chief counsel to NLRB Chairman Mark Gaston Pearce.

The issue of the NLRB is particularly important for Democrats, who feared the Senate would be unable to fix the nominations process before the board lost its quorum of members (and thus ability to act) on August 27.

Several Republicans, including Sen. Orrin Hatch (R) of Utah, had long held that removing the two NLRB nominees from the mix would allow Republicans to agree to move the larger package of nominees.

"Our view is they were illegally, unconstitutionally appointed," says Sen. John Thune (R) of South Dakota, "and that’s an awfully difficult thing to turn the other way on."

But the rest of the deal represented a capitulation by Senate Republicans to the wishes of Reid and Democrats. Previously, liberals raged for months that the GOP was holding up nominees to the CFPB or the EPA because it didn't like the agencies, not because it had actual complaints about the nominees.

"I don't understand why this body accepts [that] this political stalemate isn’t going to end in more government or less government, but just bad government," said Sen. Elizabeth Warren (D) of Massachusetts on the Senate floor Monday.

The outcome of this Senate debate harked back to 2005, when a "Gang of 14" including Senator McCain, stopped a GOP move to change the rules on judicial nominations because of Democratic filibusters. And Sen. Lamar Alexander (R) of Tennessee reminded Democrats that the cycles of Senate power mean a decision to change Senate rules now could backfire in the future.

"It might be a Democratic train going through the Senate one year, but a year and a half from now it might be the tea party express, and some of them might not like that," says Senator Alexander, a leading Senate voice for compromise who worked on the bipartisan pact. "It means we will lurch back and forth, from one extreme to the other."

A nuclear end-run by Reid would also have enraged Republicans so much that bipartisan accord on legislation or judges would have been difficult, if not impossible.

"I don't see how using the nuclear option could do anything but – this is hard for the American people to believe – make the gridlock worse,” said Sen. Carl Levin (D) of Michigan, who says that he would have voted against Reid’s proposed rules change, at a breakfast with reporters sponsored by the Monitor Tuesday.

For some long-time advocates of changing Senate rules, however, the deal represented a missed opportunity.

Allowing executive nominees to be confirmed with a bare majority of the Senate "would be liberating!" Sen. Tom Harkin (D) of Iowa says he told his colleagues on Monday night. "I said, for example, 'What do Republicans have to fear?' [Obama is in office] for three years more, he's already got his [cabinet] filled, the next president might be a Republican, and they’ve got clear sailing!… The best thing would be for all of us to lock hands and put this thing behind us."

"Every time you paper it over, it gets worse," Senator Harkin says, referring the Senate’s often halting operations. "You'll smooth it for a while and then it will just keep getting worse."

And the deal didn't touch two other significant points of contention in the Senate – filibusters on Obama’s judicial nominees and on legislation – that will almost certainly flare again in the future. The Senate is set to take up a trio of judges to the D.C. Circuit Court in the weeks to come, and Republicans oppose adding judges to what’s often referred to as the second-highest court in the land. Democrats, of course, want Obama’s nominees confirmed post-haste.

“This was a stopgap,” said Carl Tobias, a law professor at the University of Richmond, in an e-mail. “The bigger issues remain, such as judicial filibusters, [where] Senate dysfunction is harming the Third Branch.”